Contrary to early theories and negative stereotypes, emotions do not diminish with old age. In fact, a growing number of studies have documented intact, and even improved, emotion regulation across the life span. Before we generalize this model of successful aging to all adults, however, we must examine possible exceptions to this phenomenon. Studies documenting age differences in these processes have focused on predominantly healthy adults, and it is unclear how physical health problems may alter the trajectory of emotional experience. The proposed research, guided by socioemotional selectivity theory, includes three studies to examine the developmental trajectory of emotional experience among people with chronic physical health conditions, and how physical health conditions influence age differences in affective well-being and strategies used to maintain wellbeing. A better understanding of the interrelationships between age, health status and affective well-being would benefit both applied and theoretical psychology. Chronic health conditions are normative among older adults, yet health psychologists often rely on clinical interventions that do not consider age differences in their design. On the other hand, interventions designed specifically for older adults are based on studies of emotion regulation among healthy individuals, not those with chronic health conditions. Moreover, it is uncertain what subgroups of older adults are at greatest risk for affective distress over time. The specific aims are: 1) to examine how physical conditions alter the developmental trajectory of affective well-being, 2) to examine genetic and environmental influences in the covariation between chronic pain and the developmental trajectory of affective well-being, 3) to examine age differences in affective well-being and emotion regulation strategies among adults with chronic health conditions, and 4) to examine how chronic health conditions influence affective well-being and emotion regulation strategies among older adults.